Cat-Proof Door Lever Latch, Portable

thingiverse

**Problem:** Our cats keep opening our lever-handle doors. Too smart for their own good! **Analysis:** They jump up, grab the handle/lever, and hang on it, wiggling around until the door unlatches & opens a bit. Then they pull/push the door bottom and get out. **Solution:** Design a device that keeps the handle from coming down - only allow it to be moved up to open, which cats can't seem to figure out (yet!). **Already been done?:** Yes, commercial versions are available, as well as some other Thingiverse designs, but all seem to require removing the door knob, installing a big lock-type unit (some with break-out pieces), then re-assembling the knob - a somewhat painful and semi-permanent solution, some of which may damage the door or finish. We've tried and installed a few types. But, we need to move the lock from door to door easily, as we move cats around. What a pain! **Solution Design Criteria:** * Slip-on, slip-off easily - no removing/replacing screws for installation * No damage to door or finish * Downward pressure on lever uses door jamb to prevent handle rotation * No restriction on upward lifting of lever to open door from either side * Same part can be used for either left-side or right-side levers on doors (symmetrical) Note that this design relies on pressure against the door jamb, so **it MUST be installed on the door jamb side of the door.** However, it is symmetrical, so it can be installed on either right or left side handles. The part is designed to be used with additional adhesive-backed felt pads to protect the door finish, and some adhesive-backed foam strips to hold the part against the lever as it rotates while opening. See the section "Adding Pads" below.